In modern carding devices, the fibers come in contact with a plurality of carding elements. The carding elements are rollers or flat or curved plates or segments, all covered with teeth. Each interaction between carding elements where fibers are separated and combed on the card is called a carding point. FIG. 1 illustrates one such example of a carding device. As an example of a carding point, the interaction between cylinder rollers and worker rollers (or workers) can be named. Typical for the carding interaction between cylinder and worker rollers; and between cylinder and doffer rollers is the partial transfer of fibers between the rollers that interact. After separating and combing the fibers at different carding points, the fibers need to be removed out of the carding machine by means of taking the fibers under the form of a web from the rollers. In order to modify fiber arrangement in the web when taking the fibers out of the card, “condenser rollers” (or condensers) can be used. The condensers are one or two rollers arranged after the doffer. These rollers condense the web coming from the doffer. FR 2821863 describes carding machine equipment, especially for doffers, workers or condensing cylinders, comprising radially-projecting teeth with attack and back surfaces. The backs of some of the teeth have notches to retain outward sliding fibers. WO 02/077338 describes a saw-tooth wire for a stripper roller for a roller card wherein the back angle of the individual teeth increases from the root to the tip of the tooth. In order to improve the delivery properties of the stripper roller to the subsequent stuffer roller, the tooth back is steep in the area of the tip, while the breast angle is large, thereby facilitating the take-over of fibers from the tambour that rotates at a higher speed.
By giving the condenser a lower speed than the previous roller, and by using higher wires with lower point densities, they collect more web per given surface area and condense the fiber into a heavier web. The diameter of the condenser rollers should be large enough in order to control the heavier web. Due to this condensing action, fibers are more vertically and more randomly orientated, compared to the strong orientation in production direction of the fibers on the doffer.
From experience it is known that the condenser rollers should not exceed a certain maximum speed for instance 200 m/min. Speed causes problems such as loosing fibers (fiber fly); selvages of the web which tend to form fringes or the web itself is torn and incomplete transfer of the web from the condenser roller to the next roller (loading) which requires that the carding machine is stopped from time to time to clean the loaded rollers. Thus these mentioned problems lead to impairment in production and product quality.